Adding Custom validations in Struts 1.3 Validator

The validator-rules.xml file in Struts 1.3. is buried inside the struts-core-1.3.x.jar file whereas in earlier versions it was included in the WEB-INF folder. Because of this new location,when creating custom validations do we have to update the struts core jar file in order to add validations to validator-rules.xml file? what was the logic behind moving this file into the jar file.
Also the new validator-rules.xml file does not contain any javascript code for client side validations does this mean that the validator no longer offers client side validations